JP2695426B2 - Control device for fluid pressure actuator - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure cylinder that linearly reciprocates an operating body that operates in association with supply and discharge of a fluid such as liquid or gas, a rotating fluid pressure motor, and a reciprocating fluid motor. The present invention relates to a control device that stops a fluid pressure actuator such as a swinging oscillating motor at a predetermined position and maintains the stopped position.

Background of the Invention and Background of the Invention It is often necessary to stop a device driven by a hydraulic actuator at one or more positions within the range of travel of the device. However, a reciprocating fluid pressure actuator such as a fluid pressure cylinder or a swing motor can stop its operation at an accurate position at the stroke end, and can maintain the stopped state against a large load. It is difficult to firmly stop at an accurate position during the stroke because there is a leak inside the valve or the actuator. It is also difficult to firmly stop the hydraulic motor at a predetermined rotation position.

Therefore, conventionally, a mechanical stop device, for example, a brake device, a lock device for engaging and disengaging an engaging member with a movable member,
An intermittent drive device such as a Geneva mechanism was used in combination with a fluid pressure actuator, or servo control was performed based on a position signal, but in these cases, the structure of the device becomes complicated and it is expensive. Inevitable.

Therefore, the present applicant has developed and applied for a patent for a fluid pressure motor that can be stopped accurately and firmly at a predetermined rotation position. That is disclosed in JP-A-61-285291. This fluid pressure motor generates a stop torque in the motor itself by changing the supply state of the fluid to the fluid pressure motor from the normal operating state. Since the fluid pressure motor has a plurality of fluid pressure chambers and generates a torque in the rotating body due to the pressure difference between the fluid pressure chambers, at a position where it is desired to stop the rotating body, the rotating body can be either forward or reverse. If the fluid is supplied so that the torque that pushes the rotating body back to the stop position is generated even when it rotates in that direction, the rotating body is rotated to a certain rotation position with a large stop torque,
It is possible to continue stopping at that position.

Moreover, since the characteristics of the fluid pressure motor itself are used, the structure is changed by, for example, forming a supply port for supplying the fluid to a specific position, or forming an exhaust port for allowing the outflow of the fluid from the specific position. To form,
By combining a fluid pressure actuator, which is extremely simple and is modified, with a relatively simple hydraulic circuit, the fluid pressure motor can be provided with a function of stopping at a predetermined rotational position.

However, since the above invention utilizes the structure of the fluid pressure motor itself as described above, the structure of the fluid pressure motor needs to be modified although it is simple. In addition, there is an inconvenience that the stop position is determined by the structure of the fluid pressure motor. Further, there is a problem that it cannot be applied to reciprocating fluid pressure actuators such as fluid pressure cylinders and swing motors.

The present invention is not limited to the structure of a fluid pressure actuator of the type in which relative movement between the actuator housing and the operating body is caused by supplying pressurized fluid to an appropriate number of fluid pressure chambers. Control that can be applied regardless of the structure, does not need to change the structure of the fluid pressure actuator itself, and can stop the operation at a desired position regardless of the structure of the fluid pressure actuator The object is to obtain a device and a control valve that can be suitably used for the control device.

Means for Solving the Problems In one aspect of the present invention, a fluid is supplied to one of a first fluid pressure chamber and a second fluid pressure chamber formed by an actuator housing and an operating body, and fluid is supplied from the other. Is discharged, a device for controlling a double-acting fluid pressure actuator in which the actuator housing and the operating body relatively move in both forward and reverse directions is obtained. The fluid pressure actuator may be one that reciprocates with two fluid pressure chambers such as a double-acting hydraulic cylinder or a double-acting oscillating motor, and may have two fluid pressure chambers such as a gear motor. It may be rotatable, or may be one having two or more fluid pressure chambers such as a vane motor, a radial piston motor, an oblique shaft type axial piston motor, a trochoid motor, and the like. The actuating body may be a relatively simple one such as a piston and a piston rod, a rotor and a vane, and has a complicated structure including a combination of a plurality of pistons and connecting rods and a crankshaft, such as a radial piston motor. It can be one. In either case, it is not essential that the actuating body move, and it does not matter even if the actuator housing moves.

And the control device of those fluid pressure actuators is
It is configured to include a stop control valve and a transmission device. The stop control valve is a valve housing separate from the actuator housing, a valve element provided in the valve housing so as to be movable (linear movement, rotational movement, etc.), and either the valve housing or the valve element. Including a high pressure port, a first control port and a second control port formed in the first and second control ports, and the high pressure port communicates with the first control port by the relative movement of the valve housing and the valve element in both the forward and reverse directions. And a disconnection state in which neither the first control port nor the second control port communicates with each other, and a second communication state in which the second control port communicates with each other. By transmitting the relative movement between the actuator housing and the actuating body in the direction in which the volume of the first fluid pressure chamber increases. In the direction in which the volume of the second fluid pressure chamber between the actuator housing and the actuating body is increased by causing relative movement of the stop control valve from the first communication state to the shutoff state. The relative movement causes the valve housing and the valve element to move relative to each other so that the stop control valve is moved from the second communication state to the shutoff state. The first and second control ports of the stop control valve are connected to the first and second fluid pressure chambers of the fluid pressure actuator by the first and second stop control passages, respectively, and stop with the fluid pressure actuator. A switching means is provided between the control valve and the fluid pressure source that pressurizes and supplies the fluid. The switching means includes inflow of fluid into the first fluid pressure chamber of the fluid pressure actuator and outflow of fluid from the second fluid pressure chamber, and outflow of fluid from the first fluid pressure chamber and to the second fluid pressure chamber. Operation control state that selectively allows fluid inflow and outflow with fluid flow resistance from the first and second fluid pressure chambers and stop control state that allows fluid inflow to the high pressure port of the stop control valve It is possible to switch to and.

In another aspect of the present invention, a control device for controlling the double-acting fluid pressure actuator in another form is obtained.

This control device also has a stop control valve,
It is configured to include a transmission device, first and second stop control passages, and switching means, in which the high pressure port of the stop control valve is a low pressure port. Then, the transmission device shifts the stop control valve between the valve housing and the valve element from the closed state to the first continuous state by the relative movement of the actuator housing and the operating body in the direction in which the volume of the first fluid pressure chamber increases. Directional relative movement that causes the volume of the second fluid pressure chamber between the actuator housing and actuating body to increase, and the stop control valve between the valve housing and the valve element changes from the closed state to the second communication state. In the fluid pressure actuator, the switching means causes the fluid to flow into and out of the first fluid pressure chamber of the fluid pressure actuator, and the fluid to flow out of the second fluid pressure chamber, and the first fluid pressure chamber. Of the operation control state that selectively allows the outflow of the fluid from and the inflow of the fluid to the second fluid pressure chamber, and the inflow and stop control valve with the flow resistance of the fluid to the first and second fluid pressure chambers. Low pressure Switched between stop control state which permits the flow of fluid from the bets are assumed possible.

In another aspect of the present invention, a fluid is supplied to a fluid pressure chamber formed by an actuator housing and an operating body such as a single-acting hydraulic cylinder, so that the actuator housing and the operating body move relative to each other. A device for controlling a single-acting hydraulic actuator is obtained.

This control device is also configured to include a stop control valve and a transmission device, but the stop control valve has a high pressure port and a control port formed in either of them by relative movement of the valve housing and the valve element. Is switched between a communication state in which the fluid is communicated with the valve housing and a shutoff state in which the fluid communication chamber is not communicated with each other. First, a relative state in which the stop control valve is switched from the communication state to the cutoff state is generated. And, the control port of the stop control valve is connected to the fluid pressure chamber of the fluid pressure actuator by the stop control passage, and between the fluid pressure actuator, the stop control valve, and the fluid pressure source, Operation control state that selectively allows the inflow and outflow of the fluid, and the outflow with the flow resistance of the fluid from the fluid pressure chamber while blocking the inflow of the fluid to the fluid pressure chamber without passing through the stop control valve. And a stop control state capable of switching to a stop control state in which fluid is allowed to flow into the high pressure port of the stop control valve.

In the control device of each of the above aspects, the stop control valve may be in a stop control state only once for forward or backward movement of the reciprocating motion of the fluid pressure actuator, or for one rotation, and the stop control may be performed a plurality of times. It may be in a state.

According to the present invention, various control valves that can be suitably used as stop control valves in the above various control devices can be obtained.

For example, the valve housing includes a valve housing, a valve element reciprocally provided in the valve housing, and a first port, a second port, and a third port formed in any of the valve housing and the valve element. One forward or backward movement of the third port causes the third port to communicate with the first port, a first communication state, a disconnection state in which neither the first port nor the second port communicates, and a second communication state with the second port. A control valve is obtained in which a cycle consisting of three states, that is, a communicating state, is repeated a plurality of cycles.

In addition, a valve housing and a valve element reciprocally provided in the valve housing and a high pressure port, a low pressure port, a first control port and a second control port formed on either of the valve housing and the valve element are provided. Including a first communication state in which the high pressure port communicates with the first control port and the low pressure port communicates with the second control port by one forward or backward movement of the valve, and the high pressure port and the low pressure port are the first. A cycle including three states, that is, a shut-off state in which neither the control port nor the second control port is in communication, and a second communication state in which the high-pressure port is in communication with the second control port and the low-pressure port is in communication with the first control port are repeated a plurality of cycles You can get the control valve.

Further, the valve housing includes a valve housing having a valve hole with a circular cross section and a valve element rotatably fitted in the valve hole, the valve housing being formed at each end of the valve hole. The first port and the second port and the third port formed in the intermediate portion of the valve hole, while the valve element has a first spiral groove and a second spiral groove parallel to each other on the outer peripheral surface, One end of the one spiral groove is located at a position corresponding to the first port, and a first annular groove is formed along at least one of the outer peripheral surface of the valve element and the inner peripheral surface of the valve hole along the circumferential direction. Is always in communication with the first port, one end of the second spiral groove opposite to the one end of the first spiral groove is located at a position corresponding to the second port, and the second spiral groove has the same second end as the first annular groove. It is always in communication with the second port via the annular groove, and is formed between the first spiral groove and the second spiral groove. Approximately equal control valve width handed land and the diameter of the opening to the third port of the valve hole is also obtained.

Operation and Effects When the control device according to the present invention is used in combination with the fluid pressure actuator, the fluid pressure actuator is supplied with fluid in a normal form while the switching means is in the operation control state, and the fluid pressure actuator is operated in the original manner. When the switching means is switched to the stop control state by performing the rotational movement or the reciprocating movement, the supply form of the fluid to the fluid pressure actuator is changed, and the operating body of the fluid pressure actuator is firmly stopped at a predetermined position. The stop position is determined by the switching timing of the switching means from the operation control state to the stop control state and the structures of the transmission device and the stop control valve.

The stop control valve may be a rotary type in which the valve element rotates in the valve housing or a reciprocating type in which the valve element reciprocates. In the case of the rotary type, the range of one rotation, and in the case of the reciprocating type, the stop control valve is 1 An arbitrary number of ports for performing one stop control can be provided for each set within the range of forward movement or single return movement.
Further, the transmission device may transmit the relative movement between the actuator housing and the actuation body as it is to the valve housing and the valve element, or may transmit the relative movement while accelerating or decelerating. The stop position of the fluid pressure actuator can be arbitrarily set by changing the structure of the stop control valve and the transmission device or changing the combination thereof.

As is apparent from the above description, according to the control device of the present invention, the fluid pressure actuator is stopped at a desired position regardless of the construction of the fluid pressure actuator and without changing the construction. be able to.

In the control device according to claims 1 and 3, when the switching means is switched to the stop control state, the pressurized fluid is supplied to the high pressure port of the stop control valve, while the first and second fluid pressure actuators are provided. It is characterized in that the stopped state of the fluid pressure actuator is maintained by letting out a small amount of fluid from the second fluid pressure chamber.

Further, in the control device according to claim 2, a small amount of fluid is supplied to the first and second fluid pressure chambers of the fluid pressure actuator, while the fluid is caused to flow out from the low pressure port of the control valve. It is characterized in that the stopped state is maintained.

The control valve according to claims 5 and 6 is characterized in that the valve element reciprocates, and the control valve according to claim 7 is characterized in that the valve element rotates. The control valve according to claims 5 and 7 controls either supply or discharge of fluid during stop control, whereas the control valve according to claim 6 supplies or discharges fluid during stop control. It controls both and.

The control valve of the type in which the valve element rotates can utilize a transmission device capable of increasing the speed to rotate the valve element in any direction toward one direction of the fluid pressure actuator. It is suitable when the number of stop positions of the actuator is large, and has an advantage that it can be used by being directly connected to the rotary fluid pressure actuator. On the other hand, a control valve in which the valve element reciprocates is suitable for use in combination with a reciprocating fluid pressure actuator.

Moreover, if a control valve of a type that controls both supply and discharge of fluid during stop control is used as the stop control valve, the configuration of the stop control circuit can be simplified.

Examples Hereinafter, some examples of the present invention will be described in detail.

FIG. 1 shows an example of a control device for stopping a double-acting hydraulic cylinder at a plurality of positions. Reference numeral 10 indicates a hydraulic cylinder, which includes a cylinder 12 as an actuator housing, and a piston 14 and a piston rod 16 as actuating bodies. piston
On both sides of 14 are rod-side chambers that are the first and second fluid pressure chambers.
18 and a head side chamber 20 are formed. Hydraulic cylinder
A tank 28 and a hydraulic pressure source 30 serving as a fluid pressure source are connected to the tank 10 via main liquid passages 22 and 24 and an electromagnetic directional control valve 26.
Although a detailed description of the hydraulic pressure source 30 is omitted, for example, the tank 28
It is preferable to have a hydraulic pump that pumps hydraulic oil from the pump and a relief valve that allows the hydraulic oil to flow back to the tank 28 when the discharge pressure of the hydraulic pump exceeds a set pressure. The electromagnetic directional control valve 26 is a 4-port, 3-position directional control valve, which is always in the neutral position and shuts off both the rod-side chamber 18 and the head-side chamber 20 from the tank 28 and the hydraulic power source 30. By switching to either position on both sides, the hydraulic cylinder 10 is operated in either forward or reverse directions, that is, the direction in which the piston rod 16 extends or contracts.

The control device, which is an embodiment of the present invention, has a normal operation control circuit including the main liquid passages 22 and 24 and the electromagnetic directional control valve 26, which includes a stop control valve 36, an electromagnetic on-off valve 38, throttles 40 and 42, and a reverse valve. A stop control circuit including stop valves 44 and 46 and a transmission device 48 are added.

In FIG. 1, only the outer shape of the stop control valve 36 is shown. However, in order to facilitate understanding, a figure showing a simplified internal structure is shown adjacent to the figure showing the outer shape. Each liquid passage is connected to the figure on the side showing the internal structure. The stop control valve 36 includes a valve housing 50 and a valve element 52, as shown in FIGS. 2 and 3. The valve housing 50 comprises a shallow container-shaped body 54 and a flat cover 56. On the other hand, the valve element 52 utilizes the gear 60 of the gear pump and the rotary shaft 62. Gear 60
The sleeve 58 is tightly fitted around the outer periphery of the rotary shaft
While the 62 is rotatably supported by the main body 54 and the cover 56, the cover 56 is fastened to the main body 54 by bolts (not shown) so that the gap between the both side surfaces of the sleeve 58 and the gear 60 and the inner surface of the main body and the cover 56 is reduced. The liquid tightness is substantially maintained. And at the time of this assembly, the sleeve 58
The outer diameter of the sleeve 58 is made smaller than the inner diameter of the main body 54 to ensure that the gear 60 and the gear 60 rotate freely with the rotation shaft 62, and a radial gap is provided between the sleeve 58 and the main body 54. Has been formed.

The cover 56 is formed with three ports 64, 66 and 68, which are formed so that when the gear 60 rotates, the ports open in line on the arc locus drawn by the teeth 70 thereof. ing. The opening in the central port 66 is the tooth 70 of the gear 60.
The ports 64 and 68 on both sides face the tooth spaces on both sides of the tooth 70 in the closed state. Therefore,
When the gear 60 is in the position shown in FIG. 3, the stop control valve 36 is in the shut-off state in which the port 66 does not communicate with the ports 64 and 68, but if the gear 60 is rotated in the small angle clockwise direction, the port 66 is released. The communication state is such that it communicates with the port 64, and when it is rotated counterclockwise, the port 66 is in another communication state with the port 68.

Ports 64 and 68 of the stop control valve 36 are connected to the main liquid passages 24, 22 by stop control passages 72, 74, respectively,
It is a control port. And those stop control passages
Another stop control passage 76 is connected to the valves 72 and 74 via the throttles 40 and 42 and the check valves 44 and 46, and this stop control passage 76 is connected to the solenoid opening / closing valve 38.
And is connected to the tank 28 via. Further, the central port 66 is connected to the hydraulic power source 30 via the electromagnetic opening / closing valve 38 by the stop control passage 78 and serves as a high pressure port.

A pinion 82 is fixed to the rotary shaft 62 of the stop control valve 36 as shown in FIG.
Is engaged with a rack 86 connected to the piston rod 16 by a suitable means such as a connecting rod 84. Therefore, the linear relative movement between the cylinder 12 of the hydraulic cylinder 10 and the piston 14 causes the valve housing 50 and the valve 52 of the stop control valve 36 to move.
And is transmitted after being converted into a relative rotational motion with respect to the pinion 82, the connecting rod 84, the rack 86, etc.
Is composed.

 Next, the operation will be described.

Now, it is assumed that the electromagnetic directional control valve 26 is switched to the right position in FIG. 1 and the hydraulic cylinder 10 is operating in the direction in which the piston rod 16 extends. In this state, the solenoid on-off valve 38 is in the closed position. The main liquid passage 24 communicates with the liquid passage 76 via the stop control passage 72, the throttle 42 and the check valve 46, but since this liquid passage 76 is shut off by the electromagnetic opening / closing valve 38 in the closed position, Main fluid passage 24 to tank
No hydraulic fluid flows to 28. Also, piston rod
The gear 60 rotates as the gear 16 expands, and the port 64 communicates with the port 66 each time one tooth passes, but the stop control passage 78 connected to the port 66 has the electromagnetic opening / closing valve 38 in the closed position.
The hydraulic oil does not flow through this passage 78 because it is blocked by the. Further, the port 64 does not communicate with the port 68 during the rotation of the gear 60, and the working oil does not flow from the main liquid passage 24 to the main liquid passage 22 through the stop control passages 72 and 74. Further, the check valve 44 prevents the hydraulic oil from flowing from the stop control passage 72 to the stop control passage 74 via the throttle 42, the check valve 46 and the throttle 40. The flow of the hydraulic oil is throttled by the throttles 42 and 40, and the flow rate is small, so that the check valves 44 and 46 can be omitted.

When the piston rod 16 approaches the position where it should be stopped, the electromagnetic directional control valve 26 is switched to the neutral position and the electromagnetic opening / closing valve 38 is switched to the open position.
As a result, the hydraulic oil pumped from the hydraulic pressure source 30 is supplied to the port 66 of the stop control valve 36, and flows out from the port 64 or 68 to the tank 28 while being provided with flow resistance by the throttles 40 and 42. The predetermined stop position will be maintained. Furthermore, it demonstrates in detail.

In the process in which the piston rod 16 extends as shown by the arrow in FIG. 1, the valve element 52 of the stop control valve 36 rotates clockwise as shown by the arrow in FIGS. 1 and 3. If the electromagnetic directional control valve 26 and the electromagnetic on-off valve 38 are switched while the piston rod 16 is before the position to stop, the teeth 70 of the valve element 52 are not yet directly facing the port 66. , Port 66 communicates with port 64.
Therefore, from the hydraulic power source 30 to the solenoid on-off valve 38, the stop control passage 7
The hydraulic oil supplied via 8 flows into the stop control passage 72. Some of the hydraulic oil that has flowed into the stop control passage 72 is throttled 42,
Although it recirculates to the tank 28 via the check valve 46 and the stop control passage 76, the amount of this recirculation is limited by the throttle 42, so the stop control passage 72 and the head side chamber of the hydraulic cylinder 10 are controlled.
20 hydraulic pressure rises. On the other hand, the rod side chamber 18 is connected to the tank 28 via the stop control passage 74, the throttle 40, the check valve 44 and the stop control passage 76, and since hydraulic oil is not supplied, the oil pressure in the rod side chamber 18 is low, Both of these rooms 20 and 18
The piston 14 operates in the extension direction of the piston rod 16 due to the difference in hydraulic pressure. Along with that, hydraulic oil is pushed out from the rod side chamber 18 and flows back to the tank 28 via the stop control passages 74, 76 and the like. And the valve 52 rotates a small angle clockwise,
When its teeth 70 almost occlude port 66, the port
The amount of hydraulic oil supplied to the stop control passage 72 from 66 and the throttle
When the amount of the hydraulic oil that flows back to the tank 28 via 42 is balanced, the hydraulic oil is no longer supplied to the head side chamber 20, and the hydraulic cylinder 10 stops.

Further, when the switching of the electromagnetic direction switching valve 26 and the electromagnetic opening / closing valve 38 is performed after the position where the piston rod 16 should stop, the valve 52 is at the position shown in FIGS. 1 and 3. Port 66 is in communication with port 68 because it is in a position rotated by a smaller angle in the clockwise direction. Therefore,
The hydraulic oil pressure-fed from the hydraulic power source 30 is supplied to the rod side chamber 18 through the stop control passage 74, and the hydraulic cylinder 10 is operated in the direction in which the piston rod 16 contracts, contrary to the above. With this contraction, the valve element 52 rotates counterclockwise, and when the teeth 70 almost close the port 66, hydraulic oil is no longer supplied to the rod side chamber 18 and the hydraulic cylinder 10 is closed.
Operation stops.

As described above, even after the hydraulic cylinder 10 is stopped, the hydraulic oil in the rod side chamber 18 and the head side chamber 20 can flow out through the throttles 40 and 42, respectively. Then, of the two chambers 18 and 20, the volume on the side where the hydraulic oil flows out will decrease, but if the piston rod 16 moves as the volume decreases, the valve 52
Is rotated by a small angle, the working oil is supplied to the rod side chamber 18 to the head side chamber 20 of which the volume has decreased, and the piston rod 16 is returned to the original position.

As is clear from the above description, the processing accuracy of the port 66 and the valve element 52 has a significant influence on the control accuracy of the stop position of the hydraulic cylinder 10. For example, if the amount of overlap between the periphery of the port 66 and the tooth 70 is too large, the flow rate of the hydraulic oil supplied to the stop control passage 72 or 74 does not change sensitively even if the valve 52 rotates by a small angle. Therefore, the stop control accuracy is deteriorated. Although stop control is possible even if the overlap amount is negative, the stop control accuracy deteriorates as the absolute amount of the negative overlap amount increases, and the flow rate of the operating oil consumed for stop control increases. Will increase and cause energy loss. Therefore, the overlap amount should be appropriately determined in consideration of the required stop control accuracy, the size of the gap between the valve element 52 and the main body 54, and the like. In this sense, the term "blocking state" in the claims is understood to include not only the state in which the fluid such as hydraulic oil can be completely blocked but also the state in which it can be almost blocked. Should be.

In addition, although the above description has been made while ignoring the load on the hydraulic cylinder 10, since the load is usually applied in reality, the piston rod 16 is not
And the head side chamber 20 is stopped at a position where the operating force of the piston 14 and the load based on the hydraulic pressure difference between the head side chamber 20 and the rod side chamber 18 and the head side chamber 20 are in a stopped state. The teeth 70 of the valve element 52 do not necessarily remain in the position facing the port 60, as will vary depending on size and size.

As is clear from the above description, in the present embodiment, the main liquid passages 22, 24, the electromagnetic directional control valve 26, the electromagnetic opening / closing valve 38, the throttles 40, 42, the check valves 44, 46, the stop control passage 76, The switching means is constituted by 78 or the like, and this embodiment is an embodiment of the invention described in claim 1.

The valve element 52 of the stop control valve 36 uses a gear of a gear pump, but is not limited to this. For example, it is possible to use the valve 90 having the shape shown in FIG. In short, the port at a given rotational position
It does not matter as long as it has a protrusion capable of almost closing 66. Further, the formation position of the protrusion is determined based on the position where the hydraulic cylinder 10 should be stopped,
The pitch does not have to be constant, and it is not essential to form a plurality of pitches.

Further, in the above embodiment, the cylinder 12 and the stop control valve
36 and stationary, piston 14 and piston rod
Although the actuating member consisting of 16 is supposed to move, the actuating member may be stationary and the cylinder 12 and the stop control valve 36 may move.

Another embodiment of the invention according to claim 1 is shown in FIGS.
Shown in the figure. Although the stop control valve 36 is a three-port valve in the above embodiment, the stop control valve 94 of this embodiment is a four-port valve, and accordingly, the stop control circuit is modified. Restrictors 40, 42, check valves 44, 4 in the above embodiment
Instead of 6 and the stop control passage 76, a stop control passage 96 is provided and connected to the stop control valve 94.

Although the structure of the stop control valve 94 is schematically shown in FIG. 5, it is actually the structure shown in FIGS. 6 and 7. The housing 100 of the stop control valve 94 is the main body 102,
It is composed of a cover 104 and a sleeve 106, and a valve element 108 is fitted in a valve housing 100 thereof in a substantially liquid-tight manner and in a rotatable manner. The valve 108 is a body 110 and a rotary shaft 112.
And a plurality of axial grooves 114 extending in the axial direction are formed on the outer peripheral surface of the body 110, and as a result, the axial grooves 114 are formed.
A plurality of lands 115 are formed between them.

Four annular grooves 116, 118, 120 and 122 are formed on the outer peripheral surface of the sleeve 106, and ports 124, 126, 128 and 130 are formed so as to penetrate from the bottom of these annular grooves to the inner peripheral surface of the sleeve 106.

One port 124, 128 is provided for one port 126, and another port 124, 128 is provided for one port 130. The two ports 124 are in communication with each other by the annular groove 116, and the two ports 128 are in communication with each other by the annular groove 120.
In addition, as shown in FIG. 7, when the axial groove 114 of the valve element 108 faces the port 130, the port 126 is not landed.
I'm facing 115. Port 12 out of 2 ports 124
Those adjacent to 6 face the axial groove 114 and those adjacent to the port 130 face the land 115. Each of the two ports 128 has a port 126 and a port 130 between them.
It is formed at a position symmetrical to 124.

Therefore, when the valve 108 rotates a small angle in the clockwise direction indicated by the arrow from the state of FIG. 7, the port 126 communicates with the port 124, the port 130 communicates with the port 128, and the valve 108 reverses. When rotated by a small angle in the direction, the port 126 communicates with the port 128 and the port 130 communicates with the port 124.

Then, four connection ports 132, 134, 136 and 138 are formed in the main body 102, and these connection ports are formed by the annular grooves 116, 118, 120 and 122, respectively, and the continuous ports 124, 126, 12 are formed.
Communicated with 8 and 130. Therefore, the valve 108
When is rotated clockwise, the connection ports 134 and 136 communicate with each other and the connection ports 138 and 132 communicate with each other, and then the connection ports 134 and 132 are not communicated with each other. And the connection port 138 and the connection port 136 are in communication with each other.
A cycle consisting of two states will be repeated.

Actually, the stop control passages 72, 74, 78 and 96 are connected to the connection ports 132, 136, 134 and 138, and the connection port 13
2,136 and ports 124 and 128 are used as control ports, connection port 134 and port 126 are used as high pressure ports, and connection port 138 and port 130 are used as low pressure ports, but in FIG. , Each stop control passage has direct ports 124, 128, 126 and 130
It is described as if connected to.

In this embodiment, the stop control passage 78 is the stop control passage.
When communicating with either one of 72, 74, stop control passage 72,
The other of the ports 74 communicates with the stop control passage 96, and the opening edge of the port 130 and the land 151 serve as the apertures 40 and 42 in the above-described embodiment. Since the other points are the same as those of the above-mentioned embodiment, the description of the operation is omitted.

In the present embodiment, the electromagnetic directional control valve 26, the electromagnetic opening / closing valve 38, the stop control passages 78, 96 and the port 130 of the stop control valve 94 constitute a switching means.

In the above embodiment, the hydraulic cylinder 10 is stopped by supplying the hydraulic oil from the stop control valve 36 or 94, but it can also be stopped by causing the hydraulic oil to flow out from the stop control valve. An example is shown in FIG.

The stop control valve 142 of this embodiment has the same structure as the stop control valve 36 in the embodiment of FIG. 1, but the port 66 is connected to the hydraulic power source 30 in the embodiment described above. In this embodiment, it is connected to the tank 28. Further, the meshing between the rack 86 and the pinion 82 is reversed and the rotation direction of the valve element 52 of the stop control valve 142 is reversed, and the check valves 144 and 146 are also check valves 44 and 46 in the above embodiment.
And the direction of action has been reversed. Since the other points are the same as those of the embodiment of FIG. 1, the same reference numerals are given to the respective elements to show the corresponding relations, and the detailed description will be omitted, and the operation will be described.

The hydraulic cylinder 10 has a piston rod 16 as shown by the arrow.
When operating in the extension direction of, the valve element 52 of the stop control valve 142 is rotating counterclockwise as indicated by the arrow. In this state, the solenoid on-off valve 38 is in the closed position.

When the piston rod 16 reaches the vicinity of a predetermined stop position, the electromagnetic directional control valve 26 is switched to the neutral position and the electromagnetic opening / closing valve 38 is switched to the open position, and the hydraulic oil pressure-fed from the hydraulic power source 30 is transferred to the stop control passage. 76, the check valve 146, the throttle 42, the stop control passage 72 and the main liquid passage 24 to the head side chamber 20,
It is ready to be supplied to the rod side chamber 18 via the check valve 144, the throttle 40, the stop control passage 74, and the main liquid passage 22.

Now, assuming that the piston rod 16 is slightly before the stop position, the valve element 52 of the stop control valve 142 is also slightly before the position shown in FIG. 8, and the port 66 communicates with the port 68. , Port 64 is blocked. Therefore, from the rod side chamber 18, the stop control passage 74, the stop control valve 142
And a considerable amount of hydraulic oil can flow out through the stop control passage 78, whereas the head side chamber 20 can only slightly flow out due to the leakage of the stop control valve 142, and the inflow amount of hydraulic oil is Due to the restriction by the throttles 40 and 42, the hydraulic pressure in the head side chamber 20 becomes higher than that in the rod side chamber 18, and the hydraulic cylinder 10 continues to operate in the direction in which the piston rod 16 further extends. Then, when the piston rod 16 reaches the stop position, the valve element 52 in the stop control valve 142 substantially shuts off the port 66 from the port 68 and the port 64, and the stop control valve 14
The amount of hydraulic oil flowing out via 2 and the amount supplied via the throttles 40 and 42 are balanced, and the operation of the hydraulic cylinder 10 is stopped.

Further, when the electromagnetic direction switching valve 26 and the electromagnetic opening / closing valve 38 are switched, if the piston rod 16 is slightly past the position where it should be stopped, the valve element 52 of the stop control valve 145 has the eighth position.
It rotates slightly in the direction of the arrow from the position shown in the figure, and the port 66 is in communication with the port 64 and is in a state of being blocked from the port 68. Therefore, the oil pressure in the rod-side chamber 18 becomes higher than the oil pressure in the head-side chamber 20, and the hydraulic cylinder 10 operates in the direction of contraction of the piston rod 16 contrary to the above. Then, when the piston rod 16 reaches the stop position, the valve element 52 substantially shuts off the port 66 from both the ports 64 and 68, and the operation of the hydraulic cylinder 10 is stopped.

In the above description, in order to facilitate understanding, the difference in the pressure receiving area of the piston 14 with respect to the rod-side chamber 18 and the head-side chamber 20 is ignored, and it is assumed that there is no load on the piston rod 16, but this is not the case. The hydraulic cylinder 10 is a piston based on the hydraulic pressure difference between the rod side chamber 18 and the head side chamber 20.
The operation is stopped at a position where the operating force of 14 and the load on the piston rod 16 are balanced.

As is clear from the above description, in the present embodiment, the electromagnetic directional control valve 26, the electromagnetic on-off valve 38, the stop control passages 76, 7
The eight throttles 40, 42 and the check valves 144, 146 constitute a switching means, and this embodiment is an embodiment of the invention described in claim 2.

Although each of the above-mentioned embodiments controls the double-acting hydraulic cylinder, the present invention can be applied to the control of the single-acting hydraulic cylinder. FIG. 9 shows one embodiment.

In the hydraulic cylinder 150, the rod side chamber 18 is an atmospheric pressure chamber,
Supply and discharge of hydraulic oil to the head side chamber 20 and load 152
It is reciprocally operated by the pushing force of the piston rod 16 by. Supply of hydraulic oil to the head side chamber 20,
Discharge is controlled by a 3-port electromagnetic directional control valve 154.

The stop control valve 156 in this embodiment is the same as the stop control valve 36 in the embodiment of FIG. 1, but the port 68 is closed. Further, the circuit related to the rod side chamber 18 is unnecessary, and accordingly, the check valve 46 related to the head side chamber 20 is omitted. Since the other points are the same as those of the embodiment of FIG. 1, the same reference numerals are given to the respective elements to show the corresponding relationships, and the detailed description will be omitted, and the operation will be described.

When the electromagnetic directional control valve 154 is switched to the position on the right side in FIG. 9 and the hydraulic cylinder 150 is operating in the extension direction of the piston rod 16,
Shall be stopped at a predetermined position. When the piston rod 16 reaches the vicinity of the stop position, the electromagnetic directional control valve 154 is switched to the neutral position, and the electromagnetic on-off valve 38 which was in the closed position until then is switched to the open position.

At this time, if the piston rod 16 is located slightly before the stop position, the valve 52 of the stop control valve 156 is located slightly before the position shown in FIG.
Is in communication with Therefore, the hydraulic oil pumped from the hydraulic pressure source 30 is supplied to the head side chamber 20 via the stop control passage 78, the stop control valve 156 and the stop control passage 72, and the hydraulic cylinder 15
0 continues to operate in the extension direction of the piston rod 16. Then, when the piston rod 16 reaches the stop position, the valve element 52 in the stop control valve 156 substantially closes the port 66, the amount of hydraulic oil supplied via the stop control valve 156 and the amount flowing out through the throttle 42. As a result, the supply of hydraulic oil to the head side chamber 20 is stopped and the operation of the hydraulic cylinder 150 is stopped.

Further, if the piston rod 16 has passed the stop position at the time of switching the electromagnetic directional control valve 154 and the electromagnetic opening / closing valve 38, in the stop control valve 156 as well, the valve element 52 slightly moves to the position shown in FIG. It has passed, and port 66 and port 64 are blocked. Therefore, the hydraulic oil pressure-fed from the hydraulic pressure source 30 is not supplied to the head-side chamber 20, but conversely the hydraulic oil flows from the head-side chamber 20 through the stop control passages 72, 76 and the electromagnetic opening / closing valve 38 into the tank 28, and The cylinder 150 operates in the direction of contraction of the piston rod 16. Then, when the piston rod 16 reaches the stop position, the valve element 70 in the stop control valve 156 makes the port 66 and the port 64 slightly communicate with each other, and the working oil supplied from the hydraulic pressure source 30 flows through the throttle 42. The hydraulic cylinder 150 stops operating in proportion to the amount of hydraulic oil that flows out while being given resistance.

As is clear from the above description, in this embodiment, the electromagnetic directional control valve 154, the electromagnetic opening / closing valve 38, the stop control passage 76,
The switching means is constituted by 78 and the diaphragm 42, and this embodiment is an embodiment of the invention described in claim 3.

FIG. 10 shows another embodiment of the invention according to claim 1. This embodiment is similar to the embodiment shown in FIGS.
This corresponds to the stop control valve 94 changed from the rotary type to the linear movement type.

The stop control valve 170 includes a valve housing 172 and a valve element 174. The valve housing 172 has a valve hole 175 therethrough and four ports 176, 178, 180 and 182. In the valve element 174, the annular grooves 184 are formed at equal intervals on the outer peripheral surface of the cylinder so that the lands 186 are formed between the annular grooves 184, and the land 186 blocks the ports 178, 180 and 182. The dimensions and forming positions of the ports 176, 178, 180, 182, the annular groove 184, and the land 186 are determined so that the port 176 faces the annular groove 184.

Both protruding ends of the valve 174 from the valve housing 172 are
Although covered by covers 188 and 190, one end of the valve further penetrates the cover 190 and protrudes to the outside,
The projecting end is connected to the piston rod 16 of the hydraulic cylinder 10 by an appropriate connecting member 192. The connecting member 192 constitutes a transmission device that transmits the relative movement between the cylinder 12 of the hydraulic cylinder 10 and the piston rod 16 to the stop control valve 170 to cause the relative movement between the valve housing 172 and the valve element 174. Of.

The operation of this embodiment is the same as that of the embodiment of FIGS. 5 to 7 except that the valve element 174 of the stop control valve 170 moves linearly, and therefore the description thereof will be omitted. The stop control valve 170
Is an embodiment of the invention according to claim 6, and this stop control valve
If one of the ports 178 and 182 of 170 is omitted, the embodiment of the invention described in claim 5 is obtained.

FIG. 11 shows still another embodiment of the invention according to claim 1. This embodiment is similar to the embodiment shown in FIG. 5 to FIG. 7, except that the hydraulic actuator is mainly used as the hydraulic motor 200, and the stop control valve 202 and the transmission device 204. Different in composition.

The stop control valve 202 includes a valve housing 206 and a valve element 208. Valve housing 206 has a circular cross section valve hole 2
10 and ports 212, 214, 216 and 218. The ports 212 and 216 respectively communicate with annular grooves 220 and 222 formed near both ends of the valve hole 210. Also, port 214
And 218 are paired one by one, and a plurality of pairs are formed.
In this embodiment, these ports 214 and 218 are formed at intervals in the circumferential direction on a plane perpendicular to the center line of the valve hole 210, but are formed at positions displaced in the direction parallel to the center line. It is also possible to do so.

The valve 208 includes a body 224 and a rotary shaft 226. Torso 2
Two spiral grooves 228 and 230 are formed parallel to each other on the outer peripheral surface of 24, and two spiral lands 232 and 234 are formed between the spiral grooves 228 and 230. One end of the spiral groove 228 is located at a position corresponding to the port 212 in the axial direction of the valve element 208, and always communicates with the port 212 via the annular groove 220.
An end of the spiral groove 230 opposite to the one end of the spiral groove 228 is located at a position corresponding to the port 216, and always communicates with the port 216 via the annular groove 222. Spiral groove 228,230, spiral land 23
The dimensions and positions of 2,234 and ports 218,214 are such that the spiral lands 232 and 234 make port 2 at one full rotation of valve 208.
18 and 214 are closed at the same time, and before and after that position, one of the ports 218 and 214 is in the spiral groove 228 and the other is in the spiral groove 2
It is set to communicate with 30 alternately.

The transmission device 204 connects the rotary shaft 226 of the valve element 208 to the hydraulic motor 2
It is connected to the rotor of 00 and rotates the valve element 208 integrally with the rotor of the hydraulic motor 200.

In this embodiment, the electromagnetic directional control valve 26 is switched to either position on both sides of the neutral position, and the hydraulic motor 200 is operated in either forward or reverse direction with all of the plurality of electromagnetic on-off valves 38 in the closed position. Can be rotated in the direction.

When the electromagnetic directional control valve 26 is switched to the neutral position and any of the plurality of electromagnetic on-off valves 38 is switched to the open position, the ports 214 and 218 corresponding to the electromagnetic on-off valve 38 switched to the open position. Spiral Land 232,
At the position closed by 234, the hydraulic motor 200 is stopped. Even if the solenoid valve is switched in any rotational position of the hydraulic motor 200 and the valve element 208, the hydraulic motor 200 rotates to a predetermined position and stops at that position.

Also in this embodiment, when the motor 200 is loaded in one direction, the valve 218 rotates in a small angle in either direction from the position where the ports 218 and 214 are exactly closed by the spiral lands 232 and 234. Then, the hydraulic motor 200 is stopped in a state in which the rotational torque that balances the load torque is generated in the hydraulic motor 200.

As is clear from the above description, in the present embodiment, the electromagnetic directional control valve 26, the electromagnetic opening / closing valve 38, the stop control passages 78, 9
The switching means is constituted by 6 and the port 218 of the stop control valve 202. The stop control valve 202 is an embodiment of the invention described in claim 7.

If the hydraulic motor 200 always receives a load torque in one direction, it is possible to omit either one of the ports 218 and 214.

Further, the transmission device 204 is configured to integrally rotate by rotating the rotary shaft 226 of the valve element 208 and the rotor of the hydraulic motor 200, but the rotation of the rotor is increased by an appropriate means such as a gear train. It is also possible to adjust the stop position during one rotation of the hydraulic motor 200 by transmitting the speed or the speed to the rotary shaft 226.

Although some embodiments of the present invention have been described in detail above, in addition to this, for example, a stop control circuit is disclosed in Japanese Patent Application No.
According to the present invention, various modifications and improvements are made based on the knowledge of those skilled in the art, such as changing to various modes described in the specification of No. 285291 and changing the configuration of the stop control valve or the transmission device. Can be carried out.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a hydraulic cylinder control device according to an embodiment of the present invention. 2 is a front sectional view of the stop control valve shown in FIG. 1, and FIG. 3 is III in FIG.
It is a III sectional view. FIG. 4 is a side view showing a valve element according to another embodiment of the present invention. FIG. 5 is a circuit diagram of a hydraulic cylinder control device according to another embodiment of the present invention. Sixth
FIG. 7 is a front sectional view of the stop control valve shown in FIG. 5, and FIG. 7 is a sectional view taken along line VII-VII in FIG. 8 and 9 are circuit diagrams of a hydraulic cylinder control device according to still another embodiment of the present invention. FIG. 10 is a circuit diagram of a hydraulic cylinder control device that is another embodiment of the present invention. At the same time, it is a front sectional view of the control valve according to the present invention. No.
FIG. 11 is a circuit diagram of a hydraulic motor control device according to still another embodiment of the present invention, and is also a front sectional view of a control valve according to the present invention. 10: Hydraulic cylinder, 12: Cylinder 14: Piston, 18: Rod side chamber 20: Head side chamber, 26: Electromagnetic directional control valve 30: Hydraulic power source, 36: Stop control valve 38: Solenoid open / close valve, 40, 42: Restrictor 48: Transmission device, 50: Valve housing 52: Valve 64, 66, 68: Port 72, 74, 76, 78: Stop control passage 90: Valve, 94: Stop control valve 100: Valve housing 108: Valve 124, 126, 128, 130: Port 142: Stop control valve, 150: Hydraulic cylinder 154: Electromagnetic directional control valve 156, 170: Stop control valve 174: Valve 176, 178, 180, 182: Port 192: Connecting member, 200: Hydraulic motor 202: Stop control valve, 204: Transmission device 206: Valve Housing 208: Valve 212,214,216,218: Port 220,222: Annular groove 228,230: Spiral groove 232,234: Spiral land

Claims (7)

(57) [Claims] Claim: What is claimed is: 1. A fluid is supplied to one of a first fluid pressure chamber and a second fluid pressure chamber formed by an actuator housing and an actuating body, and the fluid is discharged from the other, whereby an actuator housing and A device for controlling a fluid pressure actuator in which an operating body relatively moves in both forward and reverse directions, comprising a valve housing separate from the actuator housing, a valve element movably provided in the valve housing, and the valve housings. And a high pressure port formed in any one of the valve element, a first control port and a second control port, and the high pressure port communicates with the first control port by the relative movement of the valve housing and the valve element in both forward and reverse directions. 1st communication state, 1st control port and 2nd control port not communicating, 2nd control port communicating And a stop control valve that switches to a second communication state that transmits the relative movement between the actuator housing and the operating body, and the volume of the first fluid pressure chamber between the actuator housing and the operating body is changed. Due to the relative movement in the increasing direction, the valve housing and the valve element are caused to move relative to each other in the direction in which the stop control valve is changed from the first communication state to the cutoff state, and the actuator housing and the operating body are moved to the first direction. A transmission device that causes relative movement in the direction in which the volume of the two fluid pressure chambers increases to cause the valve housing and the valve element to move the stop control valve from the second communication state to the cutoff state. First and second stop control devices that connect the first and second control ports of the stop control valve to the first and second fluid pressure chambers of the fluid pressure actuator, respectively. A fluid passage is provided between the fluid pressure source for pressurizing and supplying the fluid, the fluid pressure actuator and the stop control valve, and the fluid flows into the first fluid pressure chamber of the fluid pressure actuator and the second fluid pressure. An operation control state that selectively allows the outflow of fluid from the chamber, the outflow of fluid from the first fluid pressure chamber and the inflow of fluid to the second fluid pressure chamber, and from the first and second fluid pressure chambers. The control device for a fluid pressure actuator, comprising: switching means capable of switching to a stop control state in which the outflow with the flow resistance of the fluid and the inflow of the fluid to the high pressure port of the stop control valve are allowed. 2. A fluid is supplied to either one of a first fluid pressure chamber and a second fluid pressure chamber formed by an actuator housing and an operating body, and the fluid is discharged from the other, so that the actuator housing and A device for controlling a fluid pressure actuator in which an operating body relatively moves in both forward and reverse directions, comprising a valve housing separate from the actuator housing, a valve element movably provided in the valve housing, and the valve housings. And a first control port and a second control port formed in any one of the valve and the valve, and the low pressure port communicates with the first control port by the relative movement of the valve housing and the valve in both the forward and reverse directions. 1st communication state, 1st control port and 2nd control port not communicating, 2nd control port communicating And a stop control valve that switches to a second communication state that transmits the relative movement between the actuator housing and the operating body, and the volume of the first fluid pressure chamber between the actuator housing and the operating body is changed. Due to the relative movement in the increasing direction, the valve housing and the valve element are caused to move relative to each other in a direction to bring the stop control valve from the shut-off state to the first series communication state, and the actuator housing and the operating body are moved to the first direction. And a transmission device that causes relative movement in a direction in which the volume of the two fluid pressure chambers increases to cause the valve housing and the valve element to move the stop control valve from the cutoff state to the second communication state. First and second stop control devices that connect the first and second control ports of the stop control valve to the first and second fluid pressure chambers of the fluid pressure actuator, respectively. A fluid passage is provided between the fluid pressure source for pressurizing and supplying the fluid, the fluid pressure actuator and the stop control valve, and the fluid flows into the first fluid pressure chamber of the fluid pressure actuator and the second fluid pressure. To the first and second fluid pressure chambers, and an operation control state that selectively allows discharge of fluid from the chamber, outflow of fluid from the first fluid pressure chamber and inflow of fluid to the second fluid pressure chamber. The control device for the fluid pressure actuator, comprising: switching means capable of switching to a stop control state in which the inflow with the flow resistance of the fluid and the outflow of the fluid from the low pressure port of the stop control valve are permitted. 3. A device for controlling a fluid pressure actuator in which an actuator housing and an operating body move relative to each other by supplying a fluid to a fluid pressure chamber formed by the actuator housing and the operating body, the actuator comprising: A valve housing that is separate from the housing, and a valve element that is movably provided in the valve housing, and a high-pressure port formed in either of them by relative movement of the valve housing and the valve element. A stop control valve that switches between a communication state in which the control port communicates with a control port and a shut-off state in which the control port does not communicate, and the relative movement between the actuator housing and the operating body is transmitted to the stop control valve, and the actuator housing and the operating body The relative movement in the direction in which the volume of the fluid pressure chamber increases increases the valve housing. A transmission device that causes a relative state in which the stop control valve moves from the communication state to the cutoff state, and a stop control passage that connects a control port of the stop control valve to the fluid pressure chamber. Provided between the fluid pressure source for pressurizing and supplying a fluid, the fluid pressure actuator, and the stop control valve, and selectively allowing the fluid to flow into and out of the fluid pressure chamber of the fluid actuator. A permissible operation control state and an inflow of fluid to the fluid pressure chamber without passing through the stop control valve are permitted, and an outflow with fluid flow resistance from the fluid pressure chamber is permitted, and the high pressure of the stop control valve And a switching means capable of switching to a stop control state in which fluid is allowed to flow into the port. 4. The stop control valve is brought into the stop control state a plurality of times with respect to forward or backward movement of the reciprocating motion of the fluid pressure actuator, or one rotation.
4. The control device according to any one of 3 to 3. 5. A valve housing, a valve element provided for reciprocating operation in the valve housing, and a first port formed on any one of the valve housing and the valve element,
Including a second port and a third port, the third port communicates with the first port by one forward or backward movement of the valve, and the first port communicates with the second port. A control valve that repeats a plurality of cycles consisting of three states, a shut-off state and a second communication state that communicates with the second port. 6. A valve housing, a valve element provided in the valve housing so as to be capable of reciprocating operation, and a high pressure port formed in any one of the valve housing and the valve element,
A first control port including a low pressure port, a first control port and a second control port, the high pressure port communicating with the first control port and the low pressure port communicating with the second control port by one forward or backward movement of the valve; A communication state, a high-pressure port and a low-pressure port that do not communicate with either the first control port or the second control port, and a high-pressure port that communicates with the second control port and a low-pressure port that communicates with the first control port. A control valve that repeats a cycle consisting of three states of two communication states for multiple cycles. 7. A valve housing having a valve hole with a circular cross section, and a valve element rotatably fitted in the valve hole in a substantially liquid-tight manner, the valve housing including each of the valve holes. While having a first port and a second port formed at the end and a third port formed in the middle of the valve hole, the valve element has a first spiral groove and a second spiral that are parallel to each other on the outer peripheral surface. A groove, and one end of the first spiral groove is located at a position corresponding to the first port, and is formed along at least one of the outer peripheral surface of the valve element and the inner peripheral surface of the valve hole along the circumferential direction. Which is always in communication with the first port via the first annular groove, and one end of the second spiral groove opposite to the one end of the first spiral groove is located at a position corresponding to the second port, The second spiral groove, which is similar to the first circular groove, is always in communication with the second port, and the first spiral When the control valve width of the formed helical lands and wherein the substantially equal to the diameter of the opening into the valve hole of the third port between the second spiral groove.